The lead-acid battery is the core of the electrical system, providing current to the ignition system to start the engine as well as delivering supplemental current when the alternator can't handle high electrical system loads and acting as an electrical reservoir for excessive current.

The combustion chamber is located in the cylinder head and contains the combustion of the air-fuel mixture. This mixture is delivered by an intake valve and the waste gases from combustion are removed from the combustion chamber by the exhaust valve.

Modern car engines are cooled by liquid which circulates through the engine block and cylinder heads absorbing excess heat. This liquid is made up of half water and half antifreeze (commonly, ethylene glycol) which both keeps the water from freezing at low temperatures and raises its boiling point making heat transfer more efficient.

The crankshaft converts the reciprocating motion of the piston into the rotational motion that's used to power the vehicle and its components.

The lighting system consists of interior lights, instrument panel lighting, headlights, and taillights. Like household electrical circuits, the vehicle's lighting system is protected from current spikes by fuses and circuit breakers.